Exemplary embodiments herein generally relate to a silencer or muffler adapted to be connected to an exhaust system of an engine, and more particularly relate to an improved muffler or silencer and method of constructing same.
A conventional silencer, connected to an exhaust system of an automotive engine, includes an inlet pipe, an outlet pipe, and an expansion chamber. The inlet pipe is continuously connected to an exhaust pipe from the engine, whereas the outlet pipe is open to atmosphere. The expansion chamber provides communication between the inlet pipe and the outlet pipe.
With reference to FIGS. 11a and 11B, a known silencer 10 includes an outer shell 12 formed of a wrapped sheet of material, such as steel. In particular, a sheet of material, which can be double-layered sheet, is wrapped into an oval shape and spot-welded together. Silencer internals, including an intake pipe section 14, an exhaust pipe section 16, and a pair of supports 18, 20, are press-fit into the wrapped shell 12 and then end plates 22, 24 are secured to opposite ends of the shell 12. The end plates 22, 24 can be curl-seamed, including double-end curl-seamed, to ends of the shell 12 to prevent exhaust leakage at the seam between the end plates 22, 24 and the shell 12.
As shown, the end plates 22, 24 respectively define an intake port 26, which is in registry with an end opening 14a of the intake pipe section 14 and an exhaust port 28, which is in registry with an end opening 16a of the exhaust pipe section 16. One of the supports 18, 20 (e.g., support 20) can be generally a solid wall to divide an inner chamber of the shell 12 into separate chambers. More specifically, an opposite end 14b of the intake pipe 14 can be received through the solid separator 20 so as to direct intake exhaust into a resonator chamber 30 defined between the solid separator 20 and the adjacent end plate 24. Perforations 32 can be provided circumferentially on the intake pipe section 14 on an opposite side of the solid support 20. The other support 18 can have an aperture 34 defined therethrough for fluidly connecting the circumferential perforations 32 with an inlet end 16b of the exhaust pipe section 16.